Investigation of crystallization and amorphization dynamics of phase-change thin films using sub-nanosecond laser pulses

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We report experimental results on amorphization and crystallization dynamics of reversible phase-change (PC) thin-film samples, GeSbTe and GeBiTe, for optical disk data storage. The investigation was conducted with subnanosecond laser pulses using a pump-and-probe configuration. Amorphization of the crystalline films could be achieved with a single subnanosecond laser pulse; the amorphization dynamics follows closely the temperature kinetics induced in the irradiated spot. As for crystallization of the samples initially in the amorphous state, a single subnanosecond pulse was found to be insufficient to fully crystallize the irradiated spot, but we could crystallize the PC film (in the area under the focused spot) by applying multiple short pulses. Our multi-pulse studies reveal that the GeSbTe crystallization is dominated by the growth of nuclei whose initial formation is slow but, once formed, their subsequent growth (under a sequence of subnanosecond pulses) happens quickly. In the case of GeBiTe samples, the crystalline nuclei appear to be present in the material initially, as they grow immediately upon illumination with laser pulses. Whereas our amorphous GeSbTe samples required ~200 pulses for full crystallization, for GeBiTe samples approximately 15 pulses sufficed.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
Volume6282
DOIs
Publication statusPublished - 2006
EventOptical Data Storage 2006 - Montreal, Canada
Duration: Apr 23 2006Apr 26 2006

Other

OtherOptical Data Storage 2006
CountryCanada
CityMontreal
Period4/23/064/26/06

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Keywords

  • Amorphization
  • Crystallization
  • Data storage
  • Phase-change media
  • Short pulse laser

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

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